Mechanical Design of Out-pipe Detection Mechanisms for Pipeline Defects

Pipes in various are dominated in in the process of industrial production. To avoid the pipeline leak due to inner corrosion, it is essential to develop pipe inspection mechanisms to detect the wall thickness of the pipes used in production. The paper presents three kinds of out-pipe detection mechanisms (ODM) for different petrochemical pipeline detection demands based on eddy current testing (ECT) method. A linear inspection mechanism with fixed length is firstly proposed to detect defects of straight pipe. Secondly, a rotary inspection mechanism is designed for pipeline weld detection. Besides, an out-pipe scanning wheeled robotic mechanism is developed to detect wall thickness of pipes and avoid small obstacles such as valves on the pipelines. Lastly, detection experiments and simulations are carried out to verify the effectiveness of the designed out-pipe detection mechanisms.